Hatoful Boyfriend might be the weirdest game I know so far. Though, there's always something weirder or creepier to see.

VNs are undoubtedly the creepiest genre. Hatoful Boyfriend is tame (though still completely bizarre). Back when I first was doing research into VNs I sometimes had to immediately exit from a site or some of the stuff I've seen would have made me vomit. Needless to say I stick to reading up on the more tame, 'mainstream', less eyeball-gauging, games these days. You need a strong stomach (and probably serious mental issues) to dig into some areas of the genre. Some things you cannot un-see, and man I wish I could.